The chairman of a civilian border watch group invited by an Arizona lawmaker to address a state Senate panel has been described by a watchdog organization as a “vitriolic Mexican-basher” who courts white supremacists.

Glenn Spencer, chairman of the American Border Patrol, is set to give his assessment of the Arizona-Mexico border to the Senate’s border security committee on Thursday.

The Southern Poverty Law Center, which tracks hate groups, has a three-page online profile of Spencer, in which it says he “may have done more than anyone to spread the myth of a secret Mexican conspiracy to reconquer the Southwest.”

“It’s completely shocking” that Spencer is addressing a legislative committee, said Heidi Beirich, the center’s director of research. “We do believe that Glenn Spencer is so far out of the mainstream because of these racist views that he shouldn’t be invited in the public debate about immigration.

“There have got to be more legitimate sources about border security — professors, specialists in the field, Border Patrol agents. Something,” Beirich said.

Spencer told The Associated Press on Wednesday that he’s not racist and has never courted white supremacists to join his group.

He also said he does believe Mexicans are trying to reconquer the U.S. and that a “bloodbath” between the two countries is inevitable.

“There’s so much going on now that it’s going to blow up in our faces. It hasn’t so far because they’re doing it in a very stealthy way,” he said. “I said 15 years ago that you won’t know you’re being invaded until you try to stop it, and now we’re going to find out.”

Spencer said Republican Sen. Sylvia Allen invited him to address the committee on border security, which she chairs. He plans to tell the panel that the Border Patrol is ineffective and that more needs to be done to secure the U.S.-Mexico border.

Allen did not immediately return a message for comment by Wednesday afternoon. She was appointed in 2008 to replace a legislator who died while in office and has since been elected by voters. She has been outspoken about states’ rights legislation.

The committee’s two Democratic members on Wednesday sent a letter to Allen asking that she cancel Spencer’s presentation, saying he “represents the extreme fringe of the anti-immigration movement.”

“We all agree that our country needs to address illegal immigration and border security issues,” wrote Sens. Steve Gallardo and Robert Meza. “As policymakers, in order to solve these problems we need an unbiased, reasoned analysis of the problem based on verifiable facts and information.”

The Arizona Legislature long has been conservative when it comes to illegal immigration, but became known nationwide last year for its hardline stance after it approved a controversial immigration enforcement law.

Republican legislators ran for election or re-election last year on platforms calling for action against illegal immigration. Multiple bills targeting illegal immigrants are up for consideration this year over the objection of a group of major Arizona employers who say the measures would damage the economy and tourism.

Spencer was in the oil industry before he retired in 1992 to focus on border issues, moving from California to southern Arizona and forming the American Border Patrol. According to its website, the nonprofit American Border Patrol serves as a government watchdog and regularly monitors the border, mostly by air.

Spencer said he spends his own money to conduct surveillance on the border and is the partial owner of a small border technology company that he said can provide better security on the border.

Beirich said her group has been listing Spencer’s organization as a hate group since 2001 and started tracking Spencer’s activities around that time.